Mr. Xueming Li Profile

Xueming Li

at Yunnan Normal Univ

SPIE Involvement:

Author

Publications (3)

This will count as one of your downloads.

You will have access to both the presentation and article (if available).

DOWNLOAD NOW

This content is available for download via your institution's subscription. To access this item, please sign in to your personal account.

Email or Username Forgot your username?

Password Forgot your password?

Show

Keep me signed in

No SPIE account? Create an account

Proceedings Article | 18 March 2024 Paper

Preparation and optical properties of CoS QDs using liquid phase ultrasonic exfoliation

Kun Hu, Taiwei Zhang, Guobin Li, Ao Yang, Yiping Xia, Xueming Li, Libin Tang, Shanli Wang, Kar Seng Teng

Proceedings Volume 13104, 131044I (2024) https://doi.org/10.1117/12.3023585

KEYWORDS: Cobalt, Infrared radiation, Light absorption, Optical properties, Luminescence

Read Abstract +

Cobalt sulfide (CoS) is a zero bandgap transition metal chalcogenides (TMCs). However, the bandgap of CoS can be altered when it exists as low-dimensional material, such as quantum dots (QDs), via different preparation methods. In this work, CoS QDs were successfully prepared by liquid-phase ultrasonic exfoliation method and CoS QDs film was obtained by spin coating CoS QDs solution onto a substrate. The morphology, structural, chemical properties, thickness, vibration peaks and chemical bonds of CoS QDs were characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), energy dispersive spectrometer (EDS), atomic force microscopy (AFM), Raman spectroscopy (Raman) and X-ray photoelectron spectroscopy (XPS). The absorption and fluorescence characteristics of the CoS QDs were studied using ultraviolet-visible-near infrared (UV-Vis-NIR) and fluorescence spectroscopies. Results show that the average size of CoS QDs was 9.1 nm and average thickness was 8.4 nm and CoS QDs solution and film exhibited absorption in the infrared band. With an increase of excitation and emission wavelength, both the photoluminescence (PL) peak and photoluminescence excitation (PLE) peak of CoS QDs solution and film showed red-shift, which demonstrates Stokes shift effect and dependency on wavelength and have near-infrared luminescence characteristics. The infrared absorption and near-infrared luminescence properties of CoS QDs solution and film imply that they can be found important application in the field of infrared detection. Such novel material is expected to play a crucial role in low-cost, high performance infrared photodetector.

Proceedings Article | 18 March 2024 Paper

FeS quantum dots: preparation, structure and optical properties

Taiwei Zhang, Kun Hu, Guobin Li, Yiping Xia, Ao Yang, Xueming Li, Libin Tang, Kar Seng Teng

Proceedings Volume 13104, 131044F (2024) https://doi.org/10.1117/12.3023580

KEYWORDS: Iron, Optical properties, Infrared radiation, Light absorption, Quantum dots

Read Abstract +

Transition metal chalcogenides (TMCs) have wide-ranging applications in nanoelectronics and optoelectronics due to their unique energy band structure and excellent properties. Iron(Ⅱ) sulfide quantum dots (FeS QDs) are environmentally friendly semiconductor material and exhibit excellent near-infrared properties because of their narrow bandgap, which is essential for infrared detectors. In this paper, FeS QDs were prepared by liquid phase ultrasonic exfoliation and the solution of FeS QDs was spin-coated on a quartz substrate to form a film. The morphology, structural and optical properties of FeS QDs solutions and films were studied. FeS QDs demonstrated good dispersion with average particle size and height of approximately 11.7 and 10.4 nm, respectively. The calculated average particle size of FeS QDs was 12.7 nm using the Debye-Scherrer formula, which is in good agreement with the TEM characterization. The ultraviolet-visible-near infrared (UV-Vis-NIR) characterization of the FeS QDs solutions and films exhibited obvious absorption in the ultraviolet to near-infrared wavelength band, and the absorption was stable in the near-infrared wavelength band. The photoluminescence (PL) characterization of the FeS QDs solutions and films revealed luminescence properties in the near-infrared wavelength band, and the peak position appeared to be red-shifted with an increase in excitation wavelength, which suggests excitation wavelength-dependent luminescence properties. The FeS QDs exhibit good infrared characteristics and can potentially be used in infrared photovoltaic and photodetector.

Proceedings Article | 8 July 2022 Paper

Size-controlled synthesis SnSe2 QDs and its optical propertiess

Xingfan Chen, Xueming Li, Libin Tang, Kar Seng Teng

Proceedings Volume 12284, 122840E (2022) https://doi.org/10.1117/12.2620631

KEYWORDS: Particles, Crystals, Absorption, Raman spectroscopy, Transmission electron microscopy, Optical properties, Ultrasonics, Luminescence, Diffraction, Tin

Read Abstract +

Herein, SnSe2 QDs have successfully been prepared by liquid-phase ultrasonic exfoliation of the group IV metal-sulfide compounds. The morphology and structure of the SnSe2 QDs were characterized by transmission electron microscopy (TEM) and high-resolution transmission microscopy (HR-TEM), and the composition of the materials was analyzed by X-ray diffraction (XRD) and Raman spectroscopy (Raman). The absorbance of the samples with different wavelengths was analyzed by UV-Vis spectrophotometer, and the fluorescence intensity at different excitation wavelengths was studied by fluorescence spectrometer (PL), and the effect of different centrifugal speeds on the particle size of QDs and the spectral red-shift caused by the size effect was investigated. The average lateral sizes of SnSe₂ QDs samples obtained at centrifugal speeds of 3500, 1500 and 500 rpm were 1.86 nm, 2.73 nm, and 3.3 nm, respectively. The SnSe₂ QDs exhibited significant absorption in the infrared band and red-shift with increasing QDs size, The results demonstrated the potential use of this new material in infrared detection.

My Library

You currently do not have any folders to save your paper to! Create a new folder below.

Folder Name

Folder Description

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks. You are receiving this notice because your organization may not have SPIE eBooks access.*

*Shibboleth/Open Athens users─please sign in to access your institution's subscriptions.

To obtain this item, you may purchase the complete book in print or electronic format on SPIE.org.

ORGANIZATIONAL
Sign in with credentials provided by your organization.

Organizational Username

Organizational Password

Show/Hide Password

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members:

Non-members: ADD TO CART

Keywords/Phrases

Search In:

Publication Years